Transit vehicles and similar conveyances typically rely on fluorescent light to provide illumination to the interior of the vehicles. This has been done because historically fluorescent lighting is more efficient than other available lighting such as incandescent lighting. However, fluorescent lighting has its own drawbacks and limitations.
For example, fluorescent bulbs have a relatively short lifespan and a high current draw when compared with newer lighting technologies, and in particular with light emitting diodes (LEDs). Fluorescent lighting is not very amenable to flexible control and can be difficult to dim or to provide color variations. For example, if a fluorescent lamp filament gets too cool when attempting to dim the lamp, the lamp may simply go out and not emit any light. If current continues to flow while the electrodes are at an improper temperature, then severe rapid degradation of the filament can occur. Additionally, fluorescent lamps can shatter and emit mercury gas during maintenance, which is undesirable.
Recently, attempts have been made to incorporate LED lights into transit vehicles, in order to overcome some of the drawbacks of fluorescent lighting systems and/or to obtain certain other benefits. Some of these attempts have involved retrofitting existing fluorescent lighting fixtures to utilize LEDs. Typically, this type of retrofitting is accomplished by replacing the fluorescent light tube with a tube-shaped LED fixture having a strip of LEDs surrounded by a translucent or transparent polycarbonate tube and fitting into the electrical pin connectors that formerly supplied power and physical support to the fluorescent light tube. While this technique may allow for the replacement of fluorescent light tubes with LEDs, it still has drawbacks. For example, the light quality of such fixtures may not be ideal. Also, despite attempts to mask them, the LEDs still generally appear as visible point light sources, which is undesirable.
What is needed is an LED retrofit and method for installing the LED retrofit into a preexisting fluorescent lighting fixture that is inexpensive, easy to install and produces lighting that does not generally appear as visible point sources of light within the fixture.